1. Field of the Invention
The present invention relates to a transport apparatus, and, more particularly, to an apparatus and method for transporting substrates.
2. Prior Art
U.S. Pat. Nos. 5,151,008 and 5,577,879 disclose scara arms with end effectors. WO 94/23911 discloses an articulated arm transfer device with a drive section having a coaxial drive shaft assembly.
In accordance with one embodiment of the present invention, a substrate transport apparatus is provided comprising a drive section and a movable arm assembly. The movable arm assembly is connected to the drive section and has two driven arm assemblies. Each driven arm assembly has an inner arm connected on a common access of rotation with the drive section, an outer arm rotatably connected to the inner arm-to form a scara arm, and a transmission belt connected between the outer arm and a pulley on the drive section.
In accordance with another embodiment of the present invention, a substrate transport apparatus is provided comprising a drive section and a movable arm assembly connected to the drive section. The drive section has a coaxial drive shaft assembly with two independently rotatable drive shafts and a rotationally stationary pulley. The movable arm assembly has a first driven arm assembly connected to a first one of the drive shafts and a second driven arm assembly connected to a second one of the drive shafts. The first driven arm assembly has an inner arm connected to the first drive shaft, an outer arm pivotably connected to the inner arm to form a scara arm, and a transmission member connecting the outer arm to the rotationally stationary pulley.
In accordance with one method of the present invention, a method of transporting substrates is provided comprising steps of providing a substrate transport apparatus with a robot having a drive section with a coaxial drive shaft assembly and a movable arm assembly connected to the drive section. The movable arm assembly has two driven arm assemblies individually connected to respective drive shafts of the coaxial drive shaft assembly. The method further comprises the step of rotating a first one of the drive shafts to thereby move a first one of the driven arm assemblies. The first driven arm assembly has an inner arm that is rotated with the first drive shaft and an outer arm that is rotated relative to the inner arm. The outer arm is rotated relative to the inner arm by a first transmission belt connected between the outer arm and a rotationally stationary pulley on the drive section.
In accordance with another method of the present invention, a method of transporting substrates is provided comprising steps of providing a substrate transport apparatus with a drive section having a coaxial drive shaft assembly and a movable arm assembly connected to the drive section, and independently rotating the drive shafts to independently move the two driven arm assemblies. The movable arm assembly has two driven arm assemblies individually connected to respective drive shafts of the coaxial drive shaft assembly. Each of the two driven arm assemblies are limited to only two fully extended positions relative to the drive section. The two fully extended positions for both the drive arm assemblies are about 180xc2x0 apart.